Friction draft-gear.



No. 799,698. PATENTED SEPT. 19, 1905.

G. WBSTINGHOUSE.

FRIGTION DRAFT GEAR.

APPLICATION FILED JAN. s. 1904.

5 SHEETS-SHEET 1.

WITNESSES PATENTED SEPT. 19, 1905. TINGHOUSB.

DRAFT GEAR.

G. WBS FRIGTION APPLIOATION FILED JAN. a, 1904.

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PATBNTBD SEPT. 19, 1905. G. WEsTINGHoUsB.

PRIGTIONDRAFT GEAR.

APPLICATION FILED IAN. B. 1904.

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G. WESTINGHOUSE.

' FRIGTION DRAFT GEAR.

' PPLIoATIoN FILED JAN. s. 1904.

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vNo. 799,698.

. PATENTED SEPT. 19, 1905.

G. WESTINGHOUSB. FRICTIO-N DRAFT GEAR.

APPLICATION rum) JAN. s. 1904.

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WITNESSES 'UNITED srArEs P'ArnNr onirica.

FRICTION DRAFT-GEAR.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed January 8, 1904. Serial No. 188,175.

To 1f/ZZ whom it may concern:

Be it known th at I, GEORGE WEsTrNeHoUsn, a citizen of the United States, residing in Pittsburg, county of Allegheny, State of Pennsylvania, have invented acertain new and useful Improvement in Friction Draft-Gear, of which improvement the following is a specification.

This invention relates in general to combined spring and friction devices for yieldingly resisting strains and gradually absorbing shocks, and more particularly to that class of these appliances used as draw-gear and bufHng apparatus for railway-cars.

Heretofore in devices of this character a rigid casing having frictional surfaces has been employed to coperate with certain relatively movable friction members and a main resistance-spring. A preliminary resistancespring has also been proposed for the purpose of receiving the initial strains and transmitting the same to the friction members for forcing their surfaces into frictional engagement with each other.

The principal object of this invention is to simplify such apparatus by dispensing'with certain parts, such as the rigid casing and the preliminary spring, and to provide a device in which the main resistance-spring itself acts as a casing for holding the inclosed friction members against transverse movement, thereby reducing the number of necessary parts and the cost of manufacture while at the same time providing a compact, durable, and eflicient apparatus.

I will now describe more in detail several dierent forms of apparatus embodying my invention, reference being had to the accompanying drawings, in which- Figure 1 is a central longitudinal section of one form of my improvement, showing the same applied to the draw-bar of a railwaycar; Fig. 2, a transverse section on the line 2 2 of Fig. 1; Fig. 3, an end view of the split friction sleeve or strips as shown in Fig.

Y ment.

at each end of the coil of the spring are located a plurality of friction-segments 21, having iianges 22 extending outwardly over the ends of the coil and inclined or conical surfaces 23 engaging a corresponding inclined surface of the central wedge-blocks 24, the whole device being located between the followers 25 and 26 of the draw-bar 27 and strap 28. The inner adjacent ends of the two sets of segments are notched, as indicated at 29, and are -alternately spaced, so as to overlap each other and allow for longitudinal movement of the segments as the spring' 1s compressed when the apparatus is subjected to draft or bufling.

strains.

Between the outer faces of the segments and the inner cylindrical surface of the helical spring is located the split sleeve 30, which may, if desired, be divided longitudinally into several parts or strips, as indicated in Fig-3.

rI`he length of the friction sleeves or strips is such as to leave sufficient space between the ends of said strips and the fianges of the segments to allow for the longitudinal movement of the segmentsas the spring is compressed.

The central-wedge-blocks extend out beyond the flanges of the segments and engage the followers, so that as the apparatus shown in Fig. 1 is subjected to either a draft or buffing strain one wedge-block will be forced inward and by means of its engagement with the inclined faces of the segments will eX- pand the same transversely into frictional engagement with the sleeve or strips 30, the latter in turn bearing against the inner cylindrical surface of the helical spring, which acts as a casing and tends to hold the friction members against further transverse move- At the same time the longitudinal thrust is transmitted through the segments and their flanges to the lresistance spring itself, which is compressed according to the amount of strain applied. This same force is applied through the compression of the spring IOO IIO

to the ianges of the opposite set of segments, which are thereby pressed upon the corresponding' center wedge-block, which acts as an abutment against the fixed follower and serves to expand this .set of segments into frictional engagement with the sleeve or strips with a pressure equal to that exerted by the opposite set of segments. Frictional resistance between the segments and the sleeve or strips and also between the strips and the inner surface of the spring is thus added to the resistance of the spring for overcoming and absorbing shocks and for transmitting the stresses as applied to the draw-bar to the carframing. It will be noted that the entire force of the stress is transmitted through the wedge-block and inclined faces 23 of the segments to expand the same into frictional'engagement with the friction sleeve or strips, so' that the frictional resistance which opposes the further longitudinal movement of the segments varies according to the strain to be resisted.

When the strain upon the follower is relieved or diminished, the spring, acting by expansion upon the flanges of the opposite sets of segments, causes the same to be readily released from their frictional engagement, thus producing a very smooth and regular releasing action of the device.

The segments may be made in the form of a single integral split spring-ring, as shown in Figs. 4 and 5, and the wedge-block may llikewise be provided with longitudinal sawcuts to render the same elastic, as shown in Figs. 6 and 7.

According to the modificationshown in Figs.

8 and 12 the wedge-block 24 and segments 2l are located at one end only of the spring, while the friction sleeve or strips 30 are provided with anges 3l, which extend over the opposite end of the helical spring20 andserve to hold the strips in place.

A plate 32, having an annular recess for the Hanges of the friction-strips, may be placed between the endof the spring and the follower 26.

The heads of the segments may be provided with chambers 33 for receiving the ends of the friction-strips 30 and allow for a sufficient longitudinal movement of the segments to compress the spring to its maximum, and a spring-ring 34 may be employed for normally expanding the segments with light pressure and for holding the same in alinement and preventing any transversely-inward movement of the outer ends of the segments when heavy strains are transmitted through the inclined surfaces of the wedge-block and segments.

rlhe modification shown in Figs. 9 and 13 is similar to that just described, with the exception that a larger number of friction-strips Vare employed, and these are made substantially triangular in cross-section, with angular friction-faces for engaging' the faces of angular grooves 35, formed longitudinally in the outer surface of the segments 21, the outer faces-of the strips preferably being milled off to form a perfect bearing against the inner cylindrical surface of the helical spring. By this means the amount of frictional resistance exerted between the segments and frictionstrips is greatlyincreased and may be raised to any desired degree by varying the angle of inclination of the friction-faces of the angular strips and the angle of the friction-faces of the angular groove in the segments.

Figs. 10 and 14 show a slight modification havingiive segments, in which the spring-ring 34 is located in an annular groove in the flanges of the segments and bears against the end of the helical spring.

As shown in Fig. 11, the central wedgeblocl 24 is provided with a plurality of inclined or conical wedging-surfaces 23 for engaging a corresponding number of inclined surfaces 23 in the segments 21, thereby distributing the transverse pressure evenly throughout the length of said segments, the angle of these wedges, together with the angle between the faces of the friction-strips and the faces of the grooves, being calculated to give the desired transverse pressure upon the friction-strips for producing the proper amount of frictional resistance. The central wedge-block may also be provided with another conical wedging-surface 36, having a much sharper angle of inclination for engaging a corresponding inclined surface at thehead end of the expansible segments for the purpose of holding the segments in alinement and preventing any bending or inward transverse movement of the outer ends of the segments when the strain is applied to the other wedging-surfaces of the wedge-block.

According to the modification shown in Fig. 17 the segments 21, with their angular grooves 35, are made slightly tapering, while the friction-strips are correspondingly tapered in the reverse direction, thus securing an additional wedging action as these parts are subjected to relative longitudinal movement. By means of this construction the frictional resistance is somewhat increased for the greater strains, and the releasing action of the device is also facilitated. In this modification the ends or heads 31 of the friction-strips are turned inwardly and engage a groove 37 in the plate or ring 32, which extends over the end of the helical spring 20.

The operation is substantially the same in all of the modijcations described, the entire Yforce of the stress applied to the apparatus being transmitted through the inclined surfaces 23 to force the segments into frictional engagement with the friction-strips and to move the segments longitudinally to com press the helical spring.

When the apparatus is subjected to bufling IOO IOS

IIO

strains, the central wedge-block is forced into the segments, causing the same to move longitudinally to compress the resistance-spring and to expand transversely to engage the friction-strips with a greater or less pressure, according to the character of the strain.l

During draft strains the follower 25 and wedge-block 24 remain fixed while the follower 26 is forced forward, compressing the helical spring and moving the friction-strips longitudinally of the segments. rlhe entire force with which the spring is compressed acts through the flanges of the segments to force the same onto the central wedge-block, so that the segments and friction-strips are pressed into frictional engagement with each other in both draft and buing strains with equal effect. When the strain -is relieved in either direction after compression, the spring in expanding to its normal position forces the segments and friction-strips longitudinally in opposite directions, the friction gradually decreasing as the spring expands, thus preventing any sticking of the parts and securing a smooth release action.

One great advantage of my improved construction resides in its simple and compact form, it being no larger than the ordinary draft and bufing spring as used on railwaycars and may be readily inserted in the space between the followers usually provided for such springs.

Having now described my invention, what I claim as new. and desire to secure by Letters Patent, is-

1. In a yielding resistance mechanism, the combination with a helical spring, of relatively movable friction members having frictional engagement with each other located within said helix and held thereby against outward transverse movement.

2. A yielding resistance mechanism comprising relatively movable friction members having longitudinal engaging surfaces and a helical resistance spring surrounding said friction members and holding the same against outward transverse movement.

3. A yielding resistance mechanism comprising friction members having longitudinal frictional surfaces, a helical resistance-spring surrounding said friction members and forming a casing therefor, and a wedging device for forcing said members into frictional engagement.

4. A yielding resistance mechanism comprising a helical resistancespring, friction members located within the coil of said spring, and a wedging device for forcing said mem,- bers against the inner cylindrical surface of the coil.

5. A yielding resistance mechanism comprising ahelical spring, friction members located Within said helix, and a wedging device for expanding said friction members against the inner surface of the helix.

'6. A :yielding vresistance mechanism coinprising a plurality of segments having longi-y tudinal friction-faces, a helical spring surrounding said segments, and a wedge-block for expanding saidsegments.

7. A yielding resistance mechanism comprising a helical resistance-spring, a plurality `of segments and friction-strips having engag' .ing frictional surfaces and located within said helix, and a wedge device for forcing the seg-I ments into engagement with the frictionstrips and the strips against the inner surface' of the coils of the spring.

8. A yielding resistance mechanism com- -prlslnga helical spring, friction members having engaging frictional surfaces, and means actuated by the strain to be resisted for forcing some of said vmembers into frictional engagement with said spring.

9. A yielding resistance mechanism comprisinga helical spring arranged in alinement with the strain to be resisted and havinga friction-surface, friction members having en-V IOO paratus, the combination with a helical resistance-spring, of a plurality of segments and friction-strips arranged within the coil of the spring, and means actuated by the force of the spring when compressed for expanding the segments into frictional engagement with said strips.

l2. In a friction draw-gear and bufng apparatus, the combination with a helical resistance-spring, of a plurality of segments engaging one end of said spring, friction-strips engaging the opposite end of said spring, and means operated by the stress to be resisted for forcing the segments into frictional engagement with said vstrips and for compressing said spring.

13. Inl a friction draw-gear and buffing apparatus, the combination with a helical resistance-spring, of a plurality of segments and friction-strips located within the coil of said spring and engaging opposite ends thereof, and a central wedge-block actuated by the stress to be resisted for forcing the segments into frictional engagement with said strips.

14:. A friction draw-gear or buffing apparatus comprising a helical resistance-spring, a plurality of segments having flanges extending over one end of said helical spring, a plu- IIO rality of friction-strips having one of their ends held at the opposite end of the spring and means actuated by the stress to be resisted for forcing said segments and strips into frictional engagement With each other and for compressing' said spring.

l5. A friction draw-gear or buiing apparatus comprising a helical resistance-spring, two sets of friction members located Within said helical spring and having coacting longitudinal friction-surfaces, opposite ends of the two sets being held at opposite ends of the spring, and means actuated by the stress to be resisted for forcing said members into frictional engagement and causing a relative longitudinal movement between the sets as the spring is compressed.

16. A friction draw-gear or buing apparatus comprising a helical resistance-spring, a plurality of friction-strips located Within said helix, a plurality of segments having frictional surfaces for engaging said strips, and inclined `Wedging-surfaces, and a Wedge-block engaging said inclined surfaces for expanding said segments and transmitting the entire strain to which the spring is subjected.

17. A friction draw-gear or buing apparatus comprising a helical resistance-spring, a plurality of angular friction-strips extending wi thin said helix, a plurality of segments also extending Within said helix and having angular grooves for engaging said frictionstrips, and a Wedge device for acting upon said segments.

18. A friction draw-gear or buffing apparatus comprising a helical spring, reverselytapered friction members extending into said helix from opposite ends, and a wedge device for forcing said members into frictional engagement With each other.

19. A friction draw-gear or buiiing apparatus comprising a helical spring. frictionystrips engaging the inner surface of said helix and having one of their ends held at one end of said spring, a plurality of segments bearing at the opposite end of said spring and having frictional surfaces for engaging said friction-strips, and a Wedge device for expanding eno. WEsTINGHoUsE.

Witnesses:

E. A. WRIGHT, R. F. EMERY. 

